Note that the health regeneration is pathetically small during the actual teamfight (Warmog's and Force of Nature are both +8 health per second), which will get you +120 health for a fifteen second teamfight. Health Regeneration is much better during the laning phase, and drops off significantly in usefulness during teamfight situations.

When chasing or being chased, it may be a good idea to hold on to any movement speed increasing buffs you may have until after he has used Seismic ShardSeismic Shard as your speed increase will also increase the amount of movement speed he steals.